void
librandom::PoissonRandomDev::set_status( const DictionaryDatum& d )
{
/*
Limits on mu:
- mu >= 0 trivial
- As shown in comments in ldev(), the maximum absolute value
that can be chosen as a candidate is mu + 710 * sqrt(mu).
- We thus must require mu + 710 * sqrt(mu) < max(long).
- This is equivalent to
mu < ( 2 N + a^2 - sqrt(4 N + a^2) ) / 2
where N is the largest representable integer and a = 710.
- Numerical evaluation shows that mu < 0.999 N is safe for 32
and 64 bit doubles with a good margin.
*/
const double MU_MAX = 0.999 * std::numeric_limits< long >::max();
double new_mu = mu_;
if ( updateValue< double >( d, "lambda", new_mu ) )
{
if ( new_mu < 0 )
throw BadParameterValue( "Poisson RDV: lambda >= 0 required." );
if ( new_mu > MU_MAX )
throw BadParameterValue( String::compose( "Poisson RDV: lambda < %1 required.", MU_MAX ) );
set_lambda( new_mu );
}
}
void
librandom::GSL_BinomialRandomDev::set_status( const DictionaryDatum& d )
{
double p_new = p_;
const bool p_updated = updateValue< double >( d, "p", p_new );
long n_new = n_;
const bool n_updated = updateValue< long >( d, "n", n_new );
if ( p_new < 0. || 1. < p_new )
throw BadParameterValue( "gsl_binomial RDV: 0 <= p <= 1 required." );
if ( n_new < 1 )
throw BadParameterValue( "gsl_binomial RDV: n >= 1 required." );
// gsl_ran_binomial() returns unsigned int. To be on the safe side,
// we limit here to within ints.
const long N_MAX =
static_cast< long >( 0.9 * std::numeric_limits< int >::max() );
if ( n_new > N_MAX )
throw BadParameterValue( String::compose(
"Gsl_binomial RDV: N < %1 required.", static_cast< double >( N_MAX ) ) );
if ( n_updated || p_updated )
set_p_n( p_new, n_new );
}
void
librandom::UniformIntRandomDev::set_status( const DictionaryDatum& d )
{
long new_nmin = nmin_;
long new_nmax = nmax_;
updateValue< long >( d, "low", new_nmin );
updateValue< long >( d, "high", new_nmax );
if ( new_nmax < new_nmin )
{
throw BadParameterValue( "Uniformint RDV: low <= high required." );
}
// The following test is based on
// https://www.securecoding.cert.org/confluence/display/c/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow
// The third condition tests that we can add 1 to the difference; by the time we reach
// that clause, we know that the first two are false, so that the difference does not overflow.
if ( ( new_nmin > 0 && new_nmax < std::numeric_limits< long >::min() + new_nmin )
|| ( new_nmin < 0 && new_nmax > std::numeric_limits< long >::max() + new_nmin )
|| ( new_nmax - new_nmin > std::numeric_limits< long >::max() - 1 ) )
{
throw BadParameterValue( String::compose( "Uniformint RDV: high - low < %1 required.",
static_cast< double >( std::numeric_limits< long >::max() ) ) );
}
nmin_ = new_nmin;
nmax_ = new_nmax;
range_ = nmax_ - nmin_ + 1;
}
void
librandom::UniformIntRandomDev::set_status( const DictionaryDatum& d )
{
long new_nmin = nmin_;
long new_nmax = nmax_;
updateValue< long >( d, "low", new_nmin );
updateValue< long >( d, "high", new_nmax );
if ( new_nmax < new_nmin )
{
throw BadParameterValue( "Uniformint RDV: low <= high required." );
}
// The following test is based on
// https://www.securecoding.cert.org/confluence/display/c/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow
// Rollover cases (integer bounds min, max):
// new_nmax = n+, new_nmin = n-
//
// a) n+ >= n-:
// 1) n- >= 0: 0 <= n+ - n- <= max
// 2) n- < 0: 0 <= n+ - n-
// must confirm that n+ - n- <= max
//
// b) n+ < n-:
// 1) n- <= 0: 0 > n+ - n- >= min
// 2) n- > 0: 0 > n+ - n-
// must confirm that n+ - n- >= min
//
// Case b) is eliminated by the first test above.
// Case a) is checked by confirming that
// n+ <= max + n-
// which can not rollover when n- < 0
//
// Additionally, we set range = 1 + (n+ - n-)
// a1: n+ - n- < max
// n+ < max + n-
// a2: n+ - n- < max
//
// so we need to confirm that n+ - n- != max.
// See pull request #61
const long max = std::numeric_limits< long >::max();
if ( ( new_nmin < 0 && new_nmax >= max + new_nmin )
|| ( new_nmax - new_nmin == max ) )
{
throw BadParameterValue(
String::compose( "Uniformint RDV: high - low < %1 required.",
static_cast< double >( max ) ) );
}
nmin_ = new_nmin;
nmax_ = new_nmax;
range_ = nmax_ - nmin_ + 1;
}
void librandom::GammaRandomDev::set_status(const DictionaryDatum& d)
{
double a_new = a;
double b_new = b_;
updateValue<double>(d, "order", a_new);
updateValue<double>(d, "scale", b_new);
if ( a_new <= 0. )
throw BadParameterValue("Gamma RDV: order > 0 required.");
if ( b_new <= 0. )
throw BadParameterValue("Gamma RDV: scale > 0 required.");
set_order(a_new);
b_ = b_new;
}
void librandom::UniformIntRandomDev::set_status(const DictionaryDatum& d)
{
long new_nmin = nmin_;
long new_nmax = nmax_;
updateValue<long>(d, "low", new_nmin);
updateValue<long>(d, "high", new_nmax);
if ( new_nmax < new_nmin )
throw BadParameterValue("Uniformint RDV: low <= high required.");
if ( new_nmax - new_nmin < 0 )
throw BadParameterValue(String::compose("Uniformint RDV: high - low < %1 required.",
static_cast<double>(std::numeric_limits<long>::max())));
nmin_ = new_nmin;
nmax_ = new_nmax;
range_ = nmax_ - nmin_ + 1;
}
void
librandom::ExpRandomDev::set_status( const DictionaryDatum& d )
{
double new_lambda = lambda_;
updateValue< double >( d, "lambda", new_lambda );
if ( new_lambda <= 0. )
throw BadParameterValue( "Exponential RDV: lambda > 0 required." );
lambda_ = new_lambda;
}
void
librandom::LognormalRandomDev::set_status( const DictionaryDatum& d )
{
double new_mu = mu_;
double new_sigma = sigma_;
updateValue< double >( d, "mu", new_mu );
updateValue< double >( d, "sigma", new_sigma );
if ( new_sigma < 0. )
throw BadParameterValue( "Lognormal RDV: sigma >= 0 required." );
mu_ = new_mu;
sigma_ = new_sigma;
}
void
librandom::UniformRandomDev::set_status( const DictionaryDatum& d )
{
double new_low = low_;
double new_high = high_;
updateValue< double >( d, "low", new_low );
updateValue< double >( d, "high", new_high );
if ( new_high <= new_low )
throw BadParameterValue( "Uniform RDV: low < high required." );
low_ = new_low;
high_ = new_high;
delta_ = high_ - low_;
}